can not reproduce GBU-12 does not track laser when its LST mode

[Danhopark323]

I tried GBU-12 on LST mode, but it does not track the laser or its not following it.

I made a mission using dcs briefing room and used JTAC. 

When I used my laser, it worked and when I used LST, it didnt.

When I used my laser code and watched it with F4 view, I can see it spots the laser and try to follow it, but when it comes to LST mode, it works like non-guided bomb.

To check JTAC's laser, I used Maverick with LST mode, the Maverick worked. 

GBU-12 LST NOT WORKING.trk

[rob10]

Did you set the laser code on the bomb in the REARM MENU on the ground before takeoff to whatever the JTAC is using?  You can't change the code on the bomb in the air (it's a mechanical settings on the bomb).  Changing it in the stores page is strictly for reference for guided bombs.  The MAV is different and you CAN change it in the air that's why it worked.

[Danhopark323]

Yes, I changed the laser code in the air, but I checked Wag's Video and other tutorial videos, they all set the laser code of the GBU-12 in the air.

Is this a bug or a intended? 

How do I know the JTAC's laser code before I take off? I must be outside of their radio range. 

[razo+r]

17 minutes ago, Danhopark323 said:

Yes, I changed the laser code in the air, but I checked Wag's Video and other tutorial videos, they all set the laser code of the GBU-12 in the air.

Is this a bug or a intended? 

How do I know the JTAC's laser code before I take off? I must be outside of their radio range. 

The behaviour has changed. You cannot set the laser code of the bomb in the air anymore, you have to set it on ground by pressing on the orange triangle when you select the bomb. This is intended, as rob10 said due to having no digital interface of the bomb, you have to physically set it up on ground before flight.

You only know what code the JTAC has if you have contacted him before, if you have set it up yourself, the JTAC script is running with which you can check the JTAC status via the F10 menu or if the mission creator has noted down the code in the briefing.

Edited March 6 by razo+r

[BIGNEWY]

In the mission JTAC "AIRGUN" is 1688 and "LOPER" is 1711. 

Can you confirm you set the correct laser code while on the ground in the rearm menu, and set it correctly when using the UFC?

edit: I've tested JTAC and all seems ok to me in my own mission.

thank you 

P.S welcome to the forum

[Foka]

And just to straighten up things - there is no such thing as "LST mode" in GBU-12.
LST is just a laser search/track in your TGP, that allows you to find painted target. It has nothing to do with bombs or missiles.

[ShuRugal]

This really exposes something that has been touched on in the past on these fora as an issue: JTAC needs to take laser codes from the pilot, not tell the pilot what laser code to be using.

Before the update to bomb fuzes, this was a procedural nitpick with minimal impact on gameplay.  But now that laser codes CANNOT be changed in the air for most weapons, it's a game breaking issue.

 

I realize this is going to immediately devolve into a flamewar about the DCS JTAC, but this puts us firmly into "past time for JTAC to be fixed" territory.  The DCS JTAC has always been far too inflexible.  That was tolerable when we, the players, could be flexible to make up for JTAC's inflexibility, but as mission designs in the community have become more complex and our aircraft systems have had some of their non-realistic flexibility removed, the flaws in the original implementation have become increasingly impossible to ignore.

[Danhopark323]

I read DCS F/A-18C Manual, and watched several tutorial videos, but I never knew that the yellow thing in the rearm menu was a button. (I thought they are something special)

I made a mission that JTAC uses laser code only 1688 and checked the GBU-12's code as 1688 and it worked. 

Thank you guys.  

[rob10]

6 minutes ago, Danhopark323 said:

I read DCS F/A-18C Manual, and watched several tutorial videos, but I never knew that the yellow thing in the rearm menu was a button. (I thought they are something special)

This change was made quite a while ago now, but unfortunately the manual hasn't been updated to reflect the current situation.  I'd recommend scrolling back through the changelogs for updates because there are likely other things that have changed that aren't reflected yet.  Any videos more than 6 months old you'll need to take with a few grains of salt as things have been added or changed over time.

[Silver_]

On 3/6/2025 at 10:18 AM, BIGNEWY said:

In the mission JTAC "AIRGUN" is 1688 and "LOPER" is 1711. 

Can you confirm you set the correct laser code while on the ground in the rearm menu, and set it correctly when using the UFC?

edit: I've tested JTAC and all seems ok to me in my own mission.

thank you 

P.S welcome to the forum

 

So, from what I understand, and I understand less and less, has this become just a label? (Red arrow in the drawing.)

 

A friend from the wing told me this, and I couldn't believe it. I set up the FMU-152 fuse, which is supposed to be set in the air, and it didn't work either. IT ONLY WORKS IF YOU SET IT ON THE GROUND. INCREDIBLE. Please put these drastic changes in mechanization in red letters on the ChangeLog.

[Tholozor]

The laser code is technically not part of the fuze, it's part of the guidance control section. The FMU-152 tail fuze only allows the pilot to electronically change the arming and function delay timing, nothing more.

 

Edited 14 hours ago by Tholozor

[Silver_]

10 hours ago, Tholozor said:

The laser code is technically not part of the fuze, it's part of the guidance control section. The FMU-152 tail fuze only allows the pilot to electronically change the arming and function delay timing, nothing more.

 

Thanks for the clarification, my friend. I wasn't aware of this. All of this leads to errors because in previous versions of DCS, the bomb's code could be programmed through the avionics, hence my confusion. The fuse types were removed in a patch, and in FMU-152, it was claimed to be configurable from the cockpit. I'd like to imagine that in real life it will be as you say. I've always been clear that this has never been possible in the F16, and this approach has been maintained in this aircraft but, in the F18, it's simply changed from one day to the next.

 

Conclusion: I no longer use the CODE button on the "weapons page" because it's useless. (I do use it in the TGP for LTD and LST because it needs tuning.)

Edited 3 hours ago by Silver_